Definition
Lucy is the popular name for AL 288-1, a partial skeleton of Australopithecus afarensis discovered in 1974 by Donald Johanson and Tom Gray at Hadar, Ethiopia, in sediments dated to roughly 3.2 million years ago. About 40 percent of the skeleton was recovered — pelvis, femora, ribs, vertebrae, arm bones, jaw fragments — making her, at the time, by far the most complete early hominin individual known.
The skeleton represents a small adult female, roughly 1.1 m tall and weighing around 30 kg. The pelvis, knee joint, and lower limb bones together demonstrate unambiguous habitual bipedalism, while the long arms and curved finger bones retain adaptations for climbing.
Why it matters
Where it shows up
The original skeleton is curated at the National Museum of Ethiopia in Addis Ababa, with high-quality casts in collections worldwide. The Hadar locality has produced hundreds of additional A. afarensis specimens, including the so-called First Family (AL 333), giving Lucy substantial population-level context.
The Laetoli footprint trackway in Tanzania, made by A. afarensis individuals walking through volcanic ash 3.6 mya, complements Lucy's skeletal evidence with a direct preserved record of bipedal walking — together they form the strongest case for habitual bipedalism in any pre-Homo hominin.